With more than two million breast cancer survivors in the United States, and millions more worldwide, it is no longer adequate to focus solely on curing cancer. More effective treatments, including adjuvant chemotherapy, have increased survival rates making breast cancer a disease with lifelong consequences. In many ways, the completion of treatment does not mark the end of the cancer experience, but signals the beginning of life after cancer. Therefore, it is imperative that while research continues to search for cures for cancer, it also focuses on how treatment may affect quality of life for cancer survivors. Many women with breast cancer undergoing chemotherapy report trouble with attention span, concentration and memory. Depression, anxiety, fatigue and sleep problems also are common. The primary aims of this study are to examine the cognitive effects of chemotherapy treatment in women with breast cancer and assess the degree to which cognitive dysfunction in women with breast cancer is affected by chronic fatigue, depression, anxiety, and poor sleep quality. Participants will include seventy post-menopausal women diagnosed with breast cancer who are either: 1) undergoing lumpectomy surgery followed by six months of chemotherapy or; 2) having lumpectomy surgery alone with no adjuvant chemotherapy. All participants will be evaluated on three occasions - at diagnosis (before surgery), 3-4 weeks after surgery (before chemotherapy), and approximately 7 months after surgery (after chemotherapy). Participants will complete a battery of neuropsychological tests and self-report forms assessing: intelligence, memory, attention, language, visuospatial and motor functioning, depression, anxiety, quality of sleep, and fatigue. This pilot study will be an important step toward clarifying whether there are cognitive and psychological effects of chemotherapy treatment. A long-term aim is to launch a program of research addressing the long-term cognitive and psychological sequelae of cancer treatment. The results of this initial study will be beneficial in developing hypotheses and applications for larger studies of factors that affect daily quality of life among survivors of breast cancer.